Very rare reference - It is often forgotten that Rolex did offer "ticking" watches â€“ they indeed joined the quartz trend along with many other manufactures, researching to build the ultimate quartz movement. As a result, they manufactured 1,000 watches housing the famous Beta 21 movement. In the early 1970s Rolex decided to come up with their own version of a perfect quartz movement that could be serviced by a trained watchmaker. It actually took them five years to reach their goal, but in the meantime they had already built the perfect case to house such a revolutionary caliber. The result was a very angular case with an integrated bracelet, much like the Royal Oak from Audemars Piguet. In 1975, Rolex decided to combine this case with the chronometer-certified caliber 1570 movement, launching the short-lived reference 1530, which was discontinued as soon as the first Oysterquartz watches were released in 1977. This 1530 is historically significant as it belongs to an era where Rolex almost transitioned to being a quartz-only maker. It is also a super rare reference, given that the total production is estimated below 500 to 1000 examples - (Hodinkee source) - first Rolex with sapphire glass - Serial number 5171XXX - 1977 year - Mint condition - No water resistant - Full Rolex serviced London Square - 2 years warranty -